论文标题
用游离电子对等离子体热动力学的超快动量分辨探测
Ultrafast Momentum-Resolved Probing of Plasmon Thermal Dynamics with Free Electrons
论文作者
论文摘要
超快电子显微镜的当前进展使得可以将纳米结构和电子束探测器的光学泵送与subångstrom和飞秒时空分辨率相结合。我们提出了一种理论，预测该技术可以揭示石墨烯和石墨样品中等离子体激发的富平衡动力学。在基于传播电子中光谱特征的识别基于纳米级激发的传统探测中的破坏性偏离时，我们表明，测量的测量角度分解，能量综合的非弹性电子散射可以追溯这些结构中等离子体在这些结构中的时间演化，并在这些结构中的光束进化，并为避免电子谱图提供高度的电子谱，从而避免使用电子谱，从而避免使用电子谱。以前未开发的研究方法来研究光激发的超快动力学，可以在2D半导体和其他表现出强烈热光反应的材料中理解和操纵极化子。
Current advances in ultrafast electron microscopy make it possible to combine optical pumping of a nanostructure and electron beam probing with subångstrom and femtosecond spatiotemporal resolution. We present a theory predicting that this technique can reveal a rich out-of-equilibrium dynamics of plasmon excitations in graphene and graphite samples. In a disruptive departure from the traditional probing of nanoscale excitations based on the identification of spectral features in the transmitted electrons, we show that measurement of angle-resolved, energy-integrated inelastic electron scattering can trace the temporal evolution of plasmons in these structures and provide momentum-resolved mode identification, thus avoiding the need for highly-monochromatic electron beams and the use of electron spectrometers. This previously unexplored approach to study the ultrafast dynamics of optical excitations can be of interest to understand and manipulate polaritons in 2D semiconductors and other materials exhibiting a strong thermo-optical response.
